1. Field of the Invention
This invention relates to an electric clutch for connecting the drive shaft of a prime mover with a driven shaft, such as the input shaft of a refrigeration compressor, characterized in that a movable armature member is supported by spring means for displacement by electromagnetic means from an inactive de-energized spaced position relative to a driven member connected with the driven shaft toward an active energized position in frictional engagement with the driven member, thereby to drive the driven shaft.
2. Brief Description of the Prior Art
As shown by the prior patents to Brownfield, et al., U.S. Pat. No. 5,609,232, Viegas U.S. Pat. No. 5,252,874, and Pardee U.S. Pat. No. 5,119,918, among others, it is well known in the prior art to provide electromagnetic clutches for connecting a drive shaft (for example, an engine shaft) to a driven shaft (for example, the input shaft of a refrigeration compressor).
In conventional electric clutches, the clutch device is driven from an external power source such as an internal combustion engine or an electric motor, or both. In the case of an internal combustion engine, a flywheel is utilized for rotational inertia. The clutch is utilized to couple a secondary device such as a compressor or a pump to the external power source.
In the aforementioned Brownfield, et al., U.S. Pat. No. 5,609,232, a contact or armature member is connected for axial sliding displacement relative to the flywheel by resilient bushing means, whereby upon the activation of electromagnetic means, the armature is slidably displaced to effect clutch engagement. Permanent magnet means bias the armature toward the disengaged position.
One drawback of these known electric clutches is that there is no restriction of the axial movement of the flywheel adapter, thereby producing line-to-line contact between the adapter and the flywheel when the magnet assembly is not excited, thereby generating an unacceptable noise level during operation.
The present invention was developed to avoid the above and other drawbacks of the known electric clutches, and to produce an improved electric clutch that is reliable and positive-acting on the one hand, and is of a cost-effective simple design on the other hand.